Field
Embodiments described generally relate to low density mineral compositions and processes for making and using same. More particularly, such embodiments relate to gypsum based compositions and processes for making and using same.
Description of the Related Art
Gypsum based composites have fire resistant properties that make them desirable for construction materials. Accordingly, panels and boards made from gypsum based composites are typically used for the construction of walls, doors, ceilings, and other construction applications.
To be considered a 90-minute fire resistant door, the door must meet the 90-minute fire rating, as measured according to the Underwriters Laboratories Method (UL) 10C, “Positive Pressure Fire Test for Door Assemblies” (2009), hereafter “UL 10C (2009)”. Conventional gypsum based panels and boards can be formulated to meet this fire rating requirement, but lack the requisite strength properties for use as a door. It has been known to “block” gypsum panels to compensate for the lack of strength, but blocking requires a significant increase in manufacturing time because the door core must be assembled from multiple pieces of material instead of just one. Blocking means to remove portions of the gypsum based panel that will form the door core and replacing those removed portions with a material having greater strength. Portions of the door panel most often blocked are areas that receive door handles, hinges, kick plates, and other things that direct high mechanical stresses on the door during use.
There is a need, therefore, for improved gypsum based compositions and panels or boards made therefrom having greater strength so as to not require blocking when used as a door core in a fire resistant door.